Introduced about a century ago, suramin remains a frontline drug for the management of early-stage East African trypanosomiasis (sleeping sickness). Cellular entry into the causative agent, the protozoan parasite Trypanosoma brucei, occurs through receptor-mediated endocytosis involving the parasite's invariant surface glycoprotein 75 (ISG75), followed by transport into the cytosol via a lysosomal transporter. The molecular basis of the trypanocidal activity of suramin remains unclear, but some evidence suggests broad, but specific, impacts on trypanosome metabolism (i.e. polypharmacology). Here we observed that suramin is rapidly accumulated in trypanosome cells proportionally to ISG75 abundance. Although we found little evidence that suramin disrupts glycolytic or glycosomal pathways, we noted increased mitochondrial ATP production, but a net decrease in cellular ATP levels. Metabolomics highlighted additional impacts on mitochondrial metabolism, including partial Krebs' cycle activation and significant accumulation of pyruvate, corroborated by increased expression of mitochondrial enzymes and transporters. Significantly, the vast majority of suramin-induced proteins were normally more abundant in the insect forms compared with the blood stage of the parasite, including several proteins associated with differentiation. We conclude that suramin has multiple and complex effects on trypanosomes, but unexpectedly partially activates mitochondrial ATP-generating activity. We propose that despite apparent compensatory mechanisms in drug-challenged cells, the suramin-induced collapse of cellular ATP ultimately leads to trypanosome cell death.
- Klíčová slova
- Trypanosoma brucei, differentiation, drug action, drug mechanisms, energy homeostasis, glycosomes, metabolomics, parasite metabolism, polypharmacology, proteomics, sleeping sickness, suramin, trypanosome,
- MeSH
- adenosintrifosfát metabolismus MeSH
- energetický metabolismus účinky léků MeSH
- flagella účinky léků metabolismus ultrastruktura MeSH
- glykolýza účinky léků MeSH
- kyselina pyrohroznová metabolismus MeSH
- membránový potenciál mitochondrií účinky léků MeSH
- metabolom účinky léků MeSH
- mikrotělíska účinky léků metabolismus ultrastruktura MeSH
- mitochondrie účinky léků metabolismus ultrastruktura MeSH
- molekulární modely MeSH
- prolin metabolismus MeSH
- proteom metabolismus MeSH
- protonové ATPasy metabolismus MeSH
- protozoální proteiny metabolismus MeSH
- suramin farmakologie MeSH
- Trypanosoma brucei brucei metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenosintrifosfát MeSH
- kyselina pyrohroznová MeSH
- prolin MeSH
- proteom MeSH
- protonové ATPasy MeSH
- protozoální proteiny MeSH
- suramin MeSH
Concentration of methanol in the medium strongly affected not only the physiology but also the cytology of Candida boidinii strain 2 cells in a methanol-limited chemostat at a constant dilution rate D 0.1/h and at low pH 3.0. The formation of large cubic peroxisomes with high alcohol oxidase (AO) activity observed at low methanol concentration (S0 3 g/L) disappeared on increasing the methanol concentration in the inflow medium. The AO activity in the cells sharply decreased, followed by accumulation of riboflavin phosphate and residual methanol in the medium. The activity of catalase was relatively stable. At methanol concentration S0 > KI (KI equal to 12 g methanol per L), which included a substantial increase in methanol dissimilation, documented by higher formaldehyde and formate dehydrogenase activities and by lower yield coefficient on methanol, the yeast cells contained large lobe-shaped peroxisomes and a smaller number of larger mitochondria. The cells formed pseudomycelium with a thick septum between the mother and daughter cells.
The de novo synthesis of pyrimidine nucleotides in the rat liver after administration of nafenopin (NFP) was studied with the aid of [14C]orotic acid; the utilization of preformed nucleosides (salvage pathways) was followed using the [14C]cytidine and [14C]thymidine. A single dose (400 mg/kg) as well as repeated doses (100 mg/kg/day) of NFP increased the concentration of the cytidine and uridine components of the acid-soluble extract (ASE) of rat liver. Increase in the concentration of the cytidine components preceded the increase in the uridine components. The uptake of [14C]cytidine by the liver of rats that had been given a single dose of NFP was observed 24 h after the administration of the drug and a decrease followed after this period. The specific activity of RNA and DNA cytosine paralleled the changes of the specific activity of ASE. A single dose of NFP had no marked effect on the uptake of [14C]orotic acid. The specific activity of the uridine components of ASE remained unaltered for 2 days. After this period it decreased because of an increase in the amount of the soluble uridine components. A mild drop of the specific activity of cytidine components of ASE occurred on the second day, the total radioactivity of cytidine components increased 24 h after the administration of NFP. The specific activity of DNA pyrimidines was markedly increased 24 h after administration of the drug. On the fourth day the specific activity of DNA cytosine in the experimental group was the same as in the control group, whereas the activity of DNA thymine was lower. Following repeated administration of NFP (100 mg/kg/day) a decreased uptake of [14C]orotic acid was observed; its utilization for the synthesis of the uridine components of ASE, expressed as total radioactivity of soluble uridine components, was continuously suppressed. No changes in the specific activity of cytidine components were observed. The specific activity of DNA cytosine and thymine was distributed unevenly. During later periods of the drug action the specific activity of cytosine increased whereas the activity of thymine was lower. This phenomenon may be accounted for by the formation of a thymidylate precursor, dUMP, directly from uridine phosphates.
- MeSH
- buněčné dělení účinky léků MeSH
- cytidin metabolismus MeSH
- DNA biosyntéza účinky léků MeSH
- inbrední kmeny potkanů MeSH
- játra cytologie účinky léků metabolismus MeSH
- kinetika MeSH
- krysa rodu Rattus MeSH
- kyselina orotová metabolismus MeSH
- mikrotělíska účinky léků ultrastruktura MeSH
- nafenopin farmakologie MeSH
- propionáty farmakologie MeSH
- pyrimidiny biosyntéza MeSH
- radioizotopy uhlíku MeSH
- referenční hodnoty MeSH
- RNA biosyntéza účinky léků MeSH
- thymidin metabolismus MeSH
- velikost orgánu účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- cytidin MeSH
- DNA MeSH
- kyselina orotová MeSH
- nafenopin MeSH
- propionáty MeSH
- pyrimidiny MeSH
- radioizotopy uhlíku MeSH
- RNA MeSH
- thymidin MeSH
- MeSH
- adrenoleukodystrofie metabolismus patologie MeSH
- chondrodysplasia punctata metabolismus MeSH
- kyseliny pipekolové krev MeSH
- lidé MeSH
- mikrotělíska metabolismus ultrastruktura MeSH
- Refsumova nemoc metabolismus patologie MeSH
- vrozené poruchy metabolismu * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- kyseliny pipekolové MeSH
- MeSH
- Chiroptera MeSH
- hadi MeSH
- játra cytologie ultrastruktura MeSH
- ještěři MeSH
- ježkovití MeSH
- kočky MeSH
- králíci MeSH
- křečci praví MeSH
- křeček rodu Mesocricetus MeSH
- krysa rodu Rattus MeSH
- kur domácí MeSH
- mikrotělíska ultrastruktura MeSH
- morčata MeSH
- organoidy ultrastruktura MeSH
- prasata MeSH
- Urodela MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- králíci MeSH
- křečci praví MeSH
- krysa rodu Rattus MeSH
- morčata MeSH
- zvířata MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
